Seat portion



FIG. 1 is a perspective view of a seat portion showing our new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a front elevational view thereof; and,

FIG. 4 is an inner perspective view thereof.

The views of the seat portion not shown form no part of the claimed design. The broken lines depicting feet and the remaining portions of a chair represent environmental elements only and form no part of the claimed design. 

The ornamental design for a seat portion, as shown and described. 